1881.] 



NATURAL SCIENCES OF PHILADELPHIA. 



163 



THE SNARE OF THE RAY SPIDER (EPEIRA RADIOSA), A NEW FORM OF 



ORB- WEB. 



By Henry C. McCook, D. D. 



In the vicinity of Philadelphia, June 14, 1881, 1 found a number 

 ■of spiders grouped not far from each other on Epeiroid webs, which 

 proved to be of a type hitherto unknown, and which I designate 

 as the Actinic or Raj'-formed Orb-web. The spider appears also 

 to be new to science, and is named Ej^eira radiosa.^ 



I. Character of the Web. 



The first example or two of the spiders collected seemed to be 

 upon nests that had been broken by ordinarj^ wear and tear in 



FiQ. 1.— The Ray Spider seated in her snare, just before drawing the trap-line. 



capturing insects ; bat the repetition of the form in a third snare, 

 particularly of the peculiar open central, caused more careful 

 examination. The result was the discovery of the remarkable 



^ Radiosa, full of rays. A closer study of the spider may compel the 

 change of its generic position. 



